Effective speech often requires the speaker to pronounce every syllable carefully and distinctly. Listeners may forgive an occasional mispronunciation or dropped syllable, but they prefer to receive intelligible speech whenever possible. When a speaker chooses to mutter his or her words in an indistinct tone, the confusing effect on the listener is known as mumbling. To mumble one's words means to deliberately utter words with little regard to intelligibility.
Sometimes a person may choose to mumble in order to confuse the listener. When a parent asks a child about the contents of a report card, for example, the child may choose to mumble an unintelligible response. The hope is that the muttered answer would appease the questioner without actually revealing much tangible information. Others may mumble when delivering bad news or when forced to make an embarrassing or incriminating confession. The listener may ask for a repetition of the mumbled portion, but may also interpret the garbled words in a more positive way.
Others may choose to mumble because they want to express a personal opinion without being completely offensive. They may speak clearly at first to communicate an official response, but then mumble a softer reply under their breath. Because a mumble is so unintelligible, the listener may have no idea the speaker is actually muttering an epithet or sarcastic response.
Some incidents of mumbling may indicate a speech impediment or a lack of self-confidence by the speaker. The speaker may have every intention of speaking clearly, but the words get swallowed up or garbled in his or her mouth before delivery. A person may also mumble whenever called upon to make an unexpected speech in public. It is not unusual for a person to mumble during a routine recitation of a pledge or a responsive reading, especially if he or she is not audible to most of the audience anyway.
While the deliberate act of mumbling is generally discouraged in formal speech, there are times when a well-timed mumble can be effective. Some people enjoy mumbling their answers when asked personal questions about their age or weight, for example. Others find it cathartic to mumble a cynical or sarcastic response out of earshot of the listener. Sometimes a well-timed mumble can speak volumes.